99 aurora hard shifting

hey guys hows it going. sorry this is my first time to the forum so sorry if i am repeating the same thing over but i really couldnt find what i was looking for.

well basically i replaced the tranny out of my 99 oldsmobile aurora and the problem i have is the hard shifting. when i first turn the car on and drive, it shifts smoothly, but as soon as i keep driving and the rpm goes up a little more then the service engine soon sign comes on in the message board on top of the stereo, then thats when it starts shifting hard whenever it shift gears. but as soon as i turn the car off and turn it back on then drive it for a lil bit then the problem comes back up.

PLEASE someone help me, i love this car but i run into problems and it costs you an arm and a leg. Thanks in advance.

most prolly - wrong tranny. there's loads of modification of it, accompanied with proper pcm programs.
what u describe is pcm not liking your new tranny cos it's wrong one

so what can i do about it

you have to access somehow the GM PartsImager2 software.
you enter your VIN there.
it will give you customized parts catalog for YOUR vehicle, with all productions codes, tranny and pcm included. then you check the prod codes you have on your new tranny.
if you got wrong tranny, you will have to reprogram/replace your PCM in order for it to work good.

thanks for the info.

i actually read something about the transmission oil pressure, i think that when i put the transmission cooler hose back on i probably put them on the wrong locating onto the radiator. does anyone have a diagram or can you tell me which hose goes to the upper part of the radiator and which one goes to the lower part. thanks in advance.